Apparatus for maintaining looms out of vibration-reinforcing phase



July 28, 1953 G. A. WINTERBURN APPARATUS FOR MAINTAINING LOOMS OUT OF VIBRATION-REINFORCING PHASE Filed May 14, 1949 70 I l2 l4 INVENTOR Fl 3 georgeA. JVnierbzzm ATTORNEYS Patented July 28, 1953 UNITED STATES PATENT OFFICE George A. Winterburn, Putnam, Conn.

Application May 14, 1949, Serial No. 98,769

4 Claims. 1

This invention relates to textile machines, and more particularly to a, method of and equipment for controlling adjacent looms used for the weaving of cloth to maintain the looms out of vibration-reinforcing phase and thus minimize vibration in the building containing the looms. In textile weaving mills, it is customary to have many looms located in a single large room, the looms being located in regular rows and columns. In each loom, the lay is oscillated through a short distance to pound the reed of the lay against the cloth as it is woven and settle the woof or filling threads (transverse threads). The lay is oscillated once for each pick or passage of a woof thread and this regular oscillatory movement of the relatively heavy lay sets up a rhythmic horizontal vibration in each loom which is transmitted to the building in which the looms are located. The vibration caused by a single loom is not too objectionable,

but when two or more adjacent looms become synchronized, the horizontal vibrations transmitted to the building reinforce rather than cancel each other. A local horizontal vibration of continually increasing intensity will be set up in the building that, if unchecked, will cause the entire building to sway objectionably and may even cause structural failure. The problem is greatest Where the looms are located on floors above the ground fioor and where loom speeds have been increased up to 50% in accord with modern practice for looms located in older buildings adapted for slower loom operating speeds.

I have found that if adjacent looms in the same column (usually placed back to back or face to face) are maintained out of vibrationreinforcing phase, objectionable vibration and swaying of the building is eliminated. In the form shown of the present invention, the looms located in different rows are interconnected or paired so that, upon the two looms of each pair getting into vibration-reinforcing phase, one of the looms automatically will be slowed down or speeded up slightly for a short period of time to throw the looms out of phase. This control serves to keep the looms out of phase without slowing or speeding up either of the looms permanently and without substantially interfering with production of the looms. Ihe term phase is used to denote vibration-reinforcing phase rather than operating phase of the looms, it being customary to mount looms face to face or back to back, in which case the looms are out,

of vibration-reinforcing phase when in the same 2 lay operating phase. However, the opposite would be true if looms facing in the same direction were paired.

An object of the present invention is to provide a method and controls for automatically maintaining paired looms out of vibration-reinforcing phase.

Further objects of the invention are to provide a method of reducing the building sway of a building in which many looms are operated simultaneously; to provide such a method in which the production rate of the looms is not substantially affected; and to generally improve loom controls of the type herein described.

Further objects, and objects relating t details and economies of construction and operation will more definitely appear from the detailed description to follow.

My invention is clearly defined in the appended claims. In the claims, as well as in the description, parts are at times identified by specific names for clarity and convenience, but such nomenclature is to be understood as having the broadest meaning consistent with the context and with the concept of my invention as distinguished from the pertinent prior art. The best form in which I have contemplated applying my invention is illustrated in the accompanying drawings forming part of this specification, in which:

Fig. 1 is a diagrammatic view showing the application of my invention t a pair of adjacent looms for controlling the motor of one of the looms. The looms are indicated as being out of vibration-reinforcing phase.

Fig. 2 is a, diagrammatic view of a portion of the mechanism shown in Fig. 1, the two looms being shown in vibration-reinforcing phase.

Fig. 3 is a diagrammatic plan layout of looms in a typical installation.

Before describing the present invention in detail, the construction of a typical power loom will first be considered in order to facilitate comprehension of the nature and operation of the present invention.

The power loom is essentially a power-driven textile machine for weaving cloth from threads. In such a machine, the parallel longitudinal or warp threads are fed past a weaving station and the woof or filling threads (transverse threads) are passed across, going under some and over others of the warp threads, the warp threads being moved into different planes to facilitate this. After each filling thread is passed through the warp threads, the filling thread is pounded into position by a part known as the reed of the lay which is oscillated a short distance by means of a crank shaft on which the lay is secured. The lay is relatively heavy and is oscillated through one cycle of operation for each pick or passage of a filling thread, a usual present-day speed of looms being 140 to 180 picks per minte. The lay is moved through a short arc, the horizontal component of the are being much greater than the vertical component. Accordingly, the rapid oscillation of this part creates a horizontal vibration in the loom that is transmitted to the building in which the loom is mounted.

Fig. 3 indicates a customary arrangement of looms in a textile weaving plant, the looms being arranged in regular rows and columns. In each column, the looms are usually mounted face to face on opposite sides of an aisle, the looms ii and H of Fig. 3 being so located. Another pair of looms l2 and M are also located in the same column and face to face on opposite sides of another aisle, the looms H and I2 being back to back and separated by a wider aisle or warp alley. The arrangement shown in Fig. 3 is extended in both rows and columns, it being customary to locate many machines in this manner in a single large room.

The looms are often driven by individual three phase induction electric motors, a separate motor being provided for each loom. The motor speed is often approximately 1750 revolutions per minute, but this speed may vary between individual looms and from time to time with the same loom. When any two of the looms, particularly two adjacent looms in the same column, come into vibration-reinforcing phase in which the lays of both looms are operated in unison (in the same direction at the same time for any sub- .stantial portionof their travel), the horizontal vibrations transmitted by both looms to the building re nforce one another and are in turn reinforced by additional rhythmic vibrations produced by the subsequent oscillations of the respectivelays. This vibration is reinforced to a greater extent as the movements of the lays of the two looms become more closely synchronized, and after a short period of time the vibration transmitted to the building may cause swaying of the entire building structure and may even become sufficiently severe to threat-en structural failure of the building.

This problem of building sway has become more acute due to the fact that loom speeds have been increased and it is common to operate looms at speeds of 140 to 180 picks per minute, the oscillating speed of the lay being correspondingly increased. The problem is particularly acute where the looms are operated at increased speeds in buildings designed for loom operation at slower speeds.

In the present invention, the individual looms are paired, it being preferable to pair adjacent looms in the same column, so that the paired looms are maintained out of vibration-reinforcing phase, the horizontal vibrations transmitted to the building by each of the paired looms tending to counteract each other. .For instance, a

loom ill of Fig.- 3 might be paired with :a loom any other row such as loom l l, 12 or 14, either in the same column :or in another colurrm. However, it is desirable for convenience of installation and eifectiveness of operation to pair the looms I and M and the looms l2 and H .of

, each column sons to keep the looms of each 4 pair with their lays moving in opposition and thus out of vibration-reinforcing phase. If the paired looms face in opposite directions this is accomplished by maintaining the looms in the same lay operating phase.

Fig. 1 illustrates diagrammatically the present invention as applied to a single pair of looms for accomplishing the above result. A rotating switch 20 is driven by and at the same speed as the constantly-rotating loom cam shaft 2| of each loom, the loom cam shaft completing a single rotation for each cycle of operation of the lay. A crank portion 22 on each of the cam shafts 2i, 2!, and extending in opposite directions in Fig. 1, indicates that the two looms of Fig. 1 are out of vibration-reinforcing phase.

Each rotating switch 20 comprises a rotor 24 mounted on the cam shaft 2 l, the rotor having an arcuate contact segment 25 extending about 180 around the rotor. The arcuate segment 25 is electrically conductive, the remainder of the rotor being electrically nonconductive. A pair of spaced brushes 26, 26 are in contact with the rotor 24 and during nearly 180 degrees of revolution of the rotor the segment 25 makes electrical contact between the brushes.

The rotatin switches 20, 20 are connected in series to control an electric circuit including a normally closed double pole time delay relay 21. Power for the circuit through the switches 20, 20 and the windings of the relay 2'! may convenient- 1y be taken from a stop motion transformer 29 customarily found on looms, the voltage usually being 12 volts.

The loom motor 30 is often of the three phase induction type having three leads 3i for supplying electric power to the motor. Two of the leads 3! are connected through the two poles of the time delay relay 2'1, actuation of the relay serving to interrupt the direct circuit through the two leads 3! connected thereto. However, a resistor 32 is connected across one pole of the time delay relay, this resistor being variable if desired to control to some extent the amount that the motor 39 is slowed upon actuation of the relay. I have found that a resistor of about watts is satisfactory.

When the circuit through the time delay relay 2! is closed, only a very small amount of the current flows through the resistor 32, but when the relay is opened the resistor is then in series with the motor 30 and serves to decrease the current supplied to the rotating field of the motor. Opening of the relay 27 serves to slow down the motor 30 somewhat, preferably to a speed of about 17-00 revolutions per minute. The relay 2-! is so arranged that, upon actuation, it will remain open for a few seconds before again closing.

The operation of the rotating switches 20, 20 is such that as the paired looms commence to operate in vibration-reinforcing phase, the circuit will be completed through both of the switches 26, 2e during aportion of the revolution of the switches, which energizes and actuates the relay 21. This will slowdown the motor 30 of the controlled loom somewhat, the motor of the other loom being unaffected. Upon automatic reclosing of the relay 2 after a short time (which may be about six seconds), the motor 30 will again be accelerated to full speed and continue at full speed untilsuch time as the switohesifl, 20 again make simultaneous contact; at which time the process will be repeated, again slowing down themotor 30 for a brief period of time.

In order to avoid completion of the abovedescribed circuit and operation of the relay 21 if one loom of the pair of looms is stopped with its switch 20 making contact, two switches 3| are located in series in the circuit with the switches 2c, 26 and the relay 21, one on each loom. If desired, the switch 34 on the controlled loom may be the stop motion switch (normally closed during operation of the loom) so that upon the stop motion switch being opened, the circuit cannot be completed so as to actuate the relay. The switch 34 on the other loom may be a microswitch located on the loom operating handle so as to open the switch automatically when the loom is shut off for any reason and to close the switch whenever the loom is operating.

The above-described arrangement provides a means of pairing looms so as to operate out of vibration-reinforcing phase. Preferably, all of the looms are so paired, but, depending upon the individual conditions, it may be sufiicient to lessen the building sway by pairing only some of the looms, the remainder of the looms being permitted to operate without phase control.

The control system may be varied somewhat to provide for difierent types of motors, the con,- trolled motor being either speeded up or slowed down slightly for a short period of time by controlling the power supply to the motor. The circuits for controlling electric motor speeds depend on the type of motor and are well known.

I claim:

1. A control system for maintaining two looms with their lays moving in opposition, the looms being operated at substantially the same speed and powered by individual motors, said system comprising: a pair of electric switches, one operated in synchronism with the lay of each loom, and a time delay relay in circuit with one of the loom motors and actuated by simultaneous operation of both switches for varying slightly the speed of said motor for a fixed period of several seconds whenever the lays begin to move in unison.

2. A control system for maintaining two looms with their lays moving in opposition, the looms being operated at substantially the same speed and powered by individual motors, said system comprising: a pair of electric switches, one operated in synchronism with the lay of each loom, and a time delay relay in circuit with one of the loom motors and actuated by simultaneous operation of both switches for slowing slightly the speed of said motor for a fixed period of several seconds whenever the lays begin to move in unison.

3. A control system for maintaining two looms with their lays moving in opposition, the looms being operated at substantially the same speed and being powered by individual electric motors, said system comprising: a pair of electric switches, one operated in synchronism with the lay of each loom, said switches being connected in series with a time delay relay having an operating period of several seconds, the time delay relay being connected to control the power supply to one of the loom motors for slowing'that motor for a fixed period of time corresponding with the operating period of the relay whenever the lays begin to move in unison.

4. A control system for maintaining two looms with their lays moving in opposition, the looms being operated at substantially the same speed and being powered by individual three phase induction electric motors, said system comprising: a pair of electric switches, one operated in syn chronism with the lay of each loom, said switches being connected in series with a time delay relay having an operating period of several seconds, the time delay relay controlling the power circuit to only one of the loom motors to interrupt the circuit through one of the phases and introduce an electrical resistance into another phase for slowing said motor for a fixed period of time corresponding with the period of the relay whenever the lays begin to move in unison.

GEORGE A. WINTERBURN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,963,087 Hay June 19, 1934 2,404,469 Wood July 23, 1946 2,459,595 Snyder Jan. 18, 1949 2,484,006 Aukenman Oct. 11, 1949 2,506,225 Kuhn et a1. May 2, 1950 

